It’s interesting to note that when Hansen talks about abrupt changes that resulted in 1 meter sea level rise every 20 years those were triggered by natural incidents. The massive fossil fuel burning and filling the atmosphere with 40% more CO2 in just some 150 years surely cant be compared to anything natural, hence its very possible that the result is also way worse than anything naturally happening in the past.

No doubt when there is a lot of ice on the planet, sea level rise have a higher chance of happening than now, so I guess we can be happy that there isn’t more ice on the planet to melt away quickly.

I still think most of the IPCC estimates are too conservative from the simple observation that Arctic ice is disappearing at an alarming rate.

I assumed sea level rise due to melting ice sheets was exponential, and so fitted an exponential curve to this data (red curve for cumulative SLR):
That equation is Cum SLR (in mm) = exp((year-2000)/4.1). If that exponential curve continues for another 16 years, then by 2030 the SLR due to meltwater will be 5 feet!! And by 2040, 57 feet!! Of course, its reasonable to expect this is an overprediction, that the melt so far is the ‘easy stuff’ and that sooner or later the ice will encounter hangups from the underlying bedrock itself which slows this rate down. It’s imperative that Glaciologists get all the resources they need to figure out the expected rate of disintegration because, as you and Hansen mention, the precedence for 3 feet of rise every 20 years exists, and we need to know if this is the case here. I don’t think IPCC does a good job pointing out how uncertain they are over this topic of future SLR. I believe people are at greater risk than they are being told and the outcome could be heartbreaking.

Thanks for the link. “IPCC… sea level rise projections… do not account for dynamic ice melting processes.” Exactly! I don’t think the general public is aware that this is so. Before I read your post I generated another SLR exponential function, based on rise from 1880-2010 (google ‘wikipedia current sea level rise’), which is SLR (inches)=exp((year-1880)/57). This gives 3.4 mm/yr rise rate for 1990-2010, and 1.6 mm/yr for the 20th century overall, so is approximately correct. It predicts 120cm (4ft) of rise by 2100, so compares well with Vermeer and Rahmstorf (2009)’s value of 75-190cm as mentioned in your article. But the big thing is this is totally due to ocean thermal expansion, since meltwater didn’t really happen until 2000 or so. Hence, the SLR by 2100 is ~4 feet excluding meltwater, and must therefore be more than 4 feet. How much more is anyone’s guess: it could be another 4 feet, it could be 14 feet! And I don’t think the general public understands this, thanks to IPCC miscommunication.

Quite. Reminds me whenever I see… a certain person commenting: I had one particularly long exchange with them here where, having finally cut off every other possible avenue, there was only one remaining possibility: he didn’t know what he was talking about, refused to learn anything new and I shouldn’t waste a single further keystroke on him. Occasionally I’ve found myself starting to here, then remembered – noooo, zero point. I kind of wish there was some way I could summarise that thread, link it to his profile and warn others: reason will fail you. Do something more useful with your typing fingers and just treat it as internet tinnitus.

I feel that the trolls are the internet equivalent of obscene phone callers – they get their kicks upsetting others. Caller ID largely cured that problem and restricting anonymity might do the same for trolls. Maybe anonymity should be provisional – you can have a nom-de-blog until you abuse it, at which point the Moderator will publish your real name and email for all the world to view. That wouldn’t impact civil discourse at all.

Excellent idea about “revoking anonymity”, but it doesn’t seem to work with the likes of omnologos, daveburton, or the unlamented John Douglas Swallow, whose data is pretty well known to us.

They seem to thrive on the negative attention, and the one we know most about, daveburton, even has a Youtube clip featuring him. Having their personal email addresses would perhaps work for anyone with the time and inclination to “reverse pester” them, bu wh here has a strong enough stomach?

I think outright banning, as with kingdube and Swallow, is the answer. Enforced “timeouts”, as appears to have happened with daveburton if I’m not mistaken, can perhaps be attempted a few times as a cure.

Then there are folks like this fella who is presently popping up on my Facebook feed: He’s just repeating stuff off of Fox News without putting any thought or research behind what he’s saying. He works 40+ hours per week and has social commitments when he’s not doing that, and probably doesn’t have the gumption or interest in the subject of climate change to do his own homework; much like i don’t have the gumption or interest to research architectural engineering before i step into a large building: I just assume other folks have the safety aspect of such figured out.

Never the less the guy is propagandizing, as he owns a small business and is quite frightened of minimum wage increases and employer obligated health insurance. He’s put it to mind that Republicans are the right folks to help him avoid these things and is willing to tow the GOP memes, regardless of subject matter, in order to be supportive of the party.

He’s currently implying geoscientists from the 1970’s were afraid of some ice age that was coming ’round the corner, without considering the amount of time it takes to get into that state. No scientist i know of is going to (or was) commit to a 2100 ice age, even if we roll back the [CO2].

Excellent video for Yale and all to absorb – truly putting things in perspective, I remember a certain resident sea-level rise expert blogging about the Britain’s Jurassic pride and joys as “precarious natural stone arches” – what is his thoughts about Dr Julie Brigham-Grette’s Greenland ice sheet vulnerable to collapse statement – just equally part of a natural process, I expect.

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